Rebuilt calipers with a seal kit because the passenger side caliper stopped opening. While calipers were off the lines drained. After replacing calipers (valve up) and bleeding the system, I still can't get consistent pressure in my brakes. Currently I need to pump the brakes 3+ times to get the brakes to engage. Not satisfactory for driving! Especially the mountain roads around where I live. . . . While bleeding the system (which I did excessively), I didn't encounter any air bubbles coming out of the release valve. Started with the rear brake drum (only one of which has a bleeder valve. . .), then the passenger, then driver. Doesn't seem to be leaking anywhere. Do I need to bleed more? Is there a valve somewhere on the master cylinder that needs to be bled?